This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The loci of the major histocompatibility complex are the most diverse loci in the genome and are largely responsible for encoding the parasite/pathogen recognition pathways used by the immune system. The considerable variation at MHC loci is hypothesized to be maintained through balancing selection, as multiple pathogens and parasites interact with the immune system. Thus, individuals with higher heterozygosity at MHC loci should have lower infection rates, possibly indicating increased immune function. We propose to examine the association between major histocompatibility complex (MHC) loci heterozygosity and malarial parasite infection in a naturally occurring population of the Black Hills Junco. The objective is to test the hypothesis that the variation at MHC loci in the Black Hills Junco is maintained through balancing selection. The evolutionary history of the BH Junco makes it an interesting model in which to test this hypothesis. A recent phylogeographic analysis of the Dark-eyed Junco revealed that the Black Hills population was likely founded by a small number of individuals and has undergone dramatic morphological changes in a very small number of generations. Thus, we expect neutral genetic variation in this taxon to be comparatively low and selection at MHC loci to be very strong. Dr. Spellman hosted a fellow from USF during the summer of 2010.